Enlarge (credit: US GAO / Flickr) Millions of routers, printers, and other devices can be remotely commandeered by a new attack that exploits a security flaw in the Universal Plug and Play network protocol, a researcher said. CallStranger, as the exploit has been named, is most useful for forcing large numbers of devices to participate in distributed denial of service—or DDoS—attacks that overwhelm third-party targets with junk traffic.